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The relationship between changes in land use and soil carbon and nitrogen was assessed in Alcalá (colombian coffee growing region), between 900 and 1600 m. Soils are Argiudolls and Melanudands and sampling units were defined according to the altitudinal gradient. Carbon and nitrogen content, C:N ratio, bulk density and 13C and 15 N abundances were measured. Significant differences (p < 0.05) were found due to altitude effect, differentiating the high zone by high C (37.06 -42.88 t ha -1 ), N (3.12-3.86 t ha -1 ) and C: N (11.17-11.97), low bulk density (0.56-0.65 g cm -3 ) and 15 N abundance (4.59-5.15 ‰). Fallow and monocultures stored more carbon in deeper layers of the soil, while most preserved sites showed low C, N contents. The 13 C in land uses ranged between -25.18‰ and -21.17 ‰, indicating that carbon was fixed mainly by C 3 plants. It was concluded that land use changes affect C stocks, due to practices like chemical fertilization; and Alcalá soils have high potential for ecosystem services related with edaphic carbon capture.Keywords: carbon sequestration in the Andes, land use changes, stable isotopes RESUMEN Se estudió la relación de cambios en el uso del terreno con el C y N edáficos, en el municipio de Alcalá (región cafetera colombiana), entre 900 y 1600 m de elevación. Los suelos son Argiudolls y Melanudands y las unidades de muestreo fueron definidas según el gradiente altitudinal. Se midieron contenidos de C y N, relación C:N, densidad aparente y abundancias de 13 C y 15 N. Se encontraron diferencias significativas (p < 0,05) por el efecto de la altura. La zona alta mostró mayores contenidos de C (37,06-42,88 t ha -1 ) y N (3,12 -3,86 t ha -1 ), mayor relación C: N (11,17 -11,97), menor densidad aparente (0.56 -0.65 g cm -3 ) y abundancia de 15N (4,59 -5,15‰). Barbechos y monocultivos almacenaron más carbono en la parte subterránea del suelo; mientras que en sitios más conservados los contenidos de C y N fueron bajos. El 13 C según los usos, fluctuó entre -25,18 y -21,27‰ indicando que la mayoría del C fue fijado por plantas C 3 . Se concluyó que los cambios en el uso afectan el almacenamiento de C, 222

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Although anthropogenic impacts could be assessed in any environment, coastal areas pose a particular challenge because of their special nature as the interface between land and sea. Therefore, this study evaluates the environmental regulatory framework for coastal interventions in Colombia, as an archetype of medium income countries (MICs), to derive implications for the environmental licensing procedure (ELP). The methods comprised two simultaneous pathways: a. An inventory of human interventions at the large scale area of the Colombian Caribbean Coast, with an estimation of the overall environmental impact; b. An analysis of the ELP in Colombia during the last 25 years. The study evidences several weaknesses, such as a consistent reduction in the number of works and activities covered in each new legislative. Moreover, the Colombian ELP currently regulates only four of the ten types of interventions with greater effect in its coastal zones. The discussions highlight some policy implications for the ELP in MICs, mainly based on how the impact of a type of intervention can be magnified in proportion to its frequency of occurrence, and the need to articulate instruments of environmental management and territorial planning. At last, the need to evolve the impact assessment of human interventions from environmental factors toward socio-natural processes is evidenced and further addressed, by the introduction of a susceptibility approach inspired on geomorphological processes. Overall, this study highlights important gaps of the Colombian ELP for coastal environments, which entails valuable lessons for MICs.